Due to the chaotic evolution of the planetary orbits in the Solar System, a close approach or even a collision could occur between Mars and the Earth in less than 5 billion years, although the odds are small.
Credit: J Vidal-Madjar, NASA, IMCCE-CNRS
To get a more fine-grained view of how this might unfold, Laskar and Gastineau ran an additional two hundred computer models, slightly changing the path of Mars each time.
All but five of them ended in a two-way collision involving the Sun, Earth, Mercury, Venus or Mars. A quarter of them saw Earth smashed to pieces.
The key to all the scenarios of extreme orbital chaos was the rock closest to the Sun, found the study, published today in the British journal Nature.
Mercury is the trigger
"Mercury is the trigger, and would be the first planet to be destabilised because it has the smallest mass," explained Laskar. At some point Mercury's orbit would get into resonance with that of Jupiter, throwing the smaller orb even more out of kilter, he said.
Once this happens, the so-called "angular momentum" from the much larger Jupiter would wreak havoc on the other inner planets' orbits too.
"The simulations indicate that Mercury, in spite of its diminutive size, poses the greatest risk to our present order," noted University of California scientists Gregory Laughlin in a commentary, also published in Nature.
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sad
I can't believe the first comment; why read a science magazine if you are so brain washed you can't learn anymore, or more likely, are scared of knowledge that makes you feel frightened and you have no control over anything...
Surely, when the sun expands
Surely, when the sun expands into a red giant in 3.5 billion years time, rather than engulfing the Earth and all the other inner planets, the changes in the Suns' size would alter the Earths' trajectory and push us and the other planets away from it? I thought the orbit of each planet in the solar system was governed by a number of factors, including the Suns size and gravitational pull, so surely we wouldn't remain in the same orbit while the Sun gradually engulfs us? I need to know the answer so that I can prepare accordingly ... hehehehe!